A telecommunications line may be identified via the CLI (calling line identification) or ANI (automatic number identification) which is transmitted over various telecommunications networks. Individual users, for example, a plurality of users of one telecommunications line, are able to be differentiated based on the query for a personal identifier, such as a PIN. The PIN is a personal secret number employed by the user to verify his or her identity to the system.
Voice-processing systems may be used for controlling switching equipment, computers or telecommunications lines.
In the context of voice-recognition systems, it is the content of the spoken utterance that is recognized. Speaker-dependent voice-recognition systems (including speaker-verification systems, speaker-identification systems, speaker-classification systems) are oriented to recognizing characteristic voice features. The speaker-dependent voice-recognition system recognizes a person on the basis of characteristic voice features of the spoken utterance. In many respects, speaker-recognition resembles voice-recognition, so that for many types of applications, it may be evident to combine both functions in one unit.
Voice-recognition algorithms are available which are able to recognize a relatively large number of words in real time. These algorithms employ theoretical probability formulations and exhibit some advantages over conventional pattern-recognition algorithms. In the context of this algorithm, a plurality of patterns per word, a special form of pattern adaptation and of the strategy for calculating spacing facilitate the implementation of word recognition for a limited circle of people. The operation of the above algorithm may be explained on the basis of three logic functions: pre-processing the voice signal (deriving the pattern from the voice signal); training (producing the reference pattern); and recognition (theoretical probability calculation). If algorithms of this kind are used for the voice-controlled operation of, for example, the functions of a telecommunications line, the problem arises of identifying the specific users of the limited circle of people. This can likewise be accomplished as a voice-controlled operation, for example, by recognizing the content of a spoken numeric string (password, PIN) and comparing it to a numeric string (password, PIN) in a database assigned to the speaker.
The drawback of such approaches is that, when communicating interactively with a voice-operated dialog system, the user must identify himself/herself to the dialog system either by his/her PIN, or must undergo a training process for the voice recognition. In the process, the user is asked to enter previously trained instruction words. Not until completing this task is the user able to take advantage of the services of the voice-operated dialog system selected by him/her. The procedure requested by the customer for identifying himself/herself to the system may vary from dialog system to dialog system.